1. Technical Field
The present invention relates to wireless communication, and more particularly, to a receiving apparatus for mitigating phase noise in an orthogonal frequency division multiplexing (hereinafter, referred to as “OFDM”) communication system, and a method for the same.
2. Background Art
The OFDM has been widely adopted as a transmission standard for a next-generation broadband communication system because the
OFDM is robust against multipath fading and has a low implementation complexity.
However, since the error rate performance of an OFDM receiver is easily deteriorated by intercarrier interference (hereinafter, referred to as “ICI”) and common phase error (hereinafter, referred to as “CPE”), which are caused by phase noise and frequency deviation (offset), it is necessary to effectively compensate for such distortion components.
In order to mitigate the effects of phase noise, most receivers require the transmission of pilot symbols.
However, the transmission of such pilot symbols reduces the transmission efficiency in an OFDM system. In order to solve such a problem, a number of studies have recently been made on a phase noise mitigation method requiring no transmission of a pilot symbol, i.e. using a blind scheme.
A recent result for a receiver having a phase noise mitigator of a blind scheme is a C-MMSPE algorithm, which was proposed in document “OFDM joint data detection and phase noise cancellation for constant modulus modulations”, IEEE Transactions on Signal Processing, pp. 2864-2868, July 2009.
The C-MMSPE algorithm can efficiently compensate for phase noise when the intensity of the phase noise is small or when a low-order modulation scheme is used, while the C-MMSPE algorithm shows serious performance degradation when the intensity of the phase noise is large or when a high-order modulation scheme is used.
The C-MMSPE algorithm is to estimate a transmitted symbol using a received symbol, in which ICI has not been mitigated at all, and to estimate phase noise with the symbol estimation value.
In this case, when the ICI exerts a large effect, the symbol estimation value becomes inaccurate, and thus the phase noise also is inaccurately estimated, so that the performance of the C-MMSPE algorithm is degraded.